/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */


package javax.management.openmbean;

// java import
//

import java.util.Set;
import java.util.TreeMap;
import java.util.Collections;
import java.util.Iterator;

// jmx import
//


/**
 * The <code>CompositeType</code> class is the <i>open type</i> class
 * whose instances describe the types of {@link CompositeData CompositeData} values.
 *
 * @since 1.5
 */
public class CompositeType extends OpenType<CompositeData> {

  /* Serial version */
  static final long serialVersionUID = -5366242454346948798L;

  /**
   * @serial Sorted mapping of the item names to their descriptions
   */
  private TreeMap<String, String> nameToDescription;

  /**
   * @serial Sorted mapping of the item names to their open types
   */
  private TreeMap<String, OpenType<?>> nameToType;

  /* As this instance is immutable, following three values need only
   * be calculated once.  */
  private transient Integer myHashCode = null;
  private transient String myToString = null;
  private transient Set<String> myNamesSet = null;


    /* *** Constructor *** */

  /**
   * Constructs a <code>CompositeType</code> instance, checking for the validity of the given
   * parameters. The validity constraints are described below for each parameter. <p> Note that the
   * contents of the three array parameters <var>itemNames</var>, <var>itemDescriptions</var> and
   * <var>itemTypes</var> are internally copied so that any subsequent modification of these arrays
   * by the caller of this constructor has no impact on the constructed <code>CompositeType</code>
   * instance. <p> The Java class name of composite data values this composite type represents (ie
   * the class name returned by the {@link OpenType#getClassName() getClassName} method) is set to
   * the string value returned by <code>CompositeData.class.getName()</code>. <p>
   *
   * @param typeName The name given to the composite type this instance represents; cannot be a null
   * or empty string. <br>&nbsp;
   * @param description The human readable description of the composite type this instance
   * represents; cannot be a null or empty string. <br>&nbsp;
   * @param itemNames The names of the items contained in the composite data values described by
   * this <code>CompositeType</code> instance; cannot be null and should contain at least one
   * element; no element can be a null or empty string. Note that the order in which the item names
   * are given is not important to differentiate a <code>CompositeType</code> instance from another;
   * the item names are internally stored sorted in ascending alphanumeric order. <br>&nbsp;
   * @param itemDescriptions The descriptions, in the same order as <var>itemNames</var>, of the
   * items contained in the composite data values described by this <code>CompositeType</code>
   * instance; should be of the same size as <var>itemNames</var>; no element can be null or an
   * empty string. <br>&nbsp;
   * @param itemTypes The open type instances, in the same order as <var>itemNames</var>, describing
   * the items contained in the composite data values described by this <code>CompositeType</code>
   * instance; should be of the same size as <var>itemNames</var>; no element can be null.
   * <br>&nbsp;
   * @throws IllegalArgumentException If <var>typeName</var> or <var>description</var> is a null or
   * empty string, or <var>itemNames</var> or <var>itemDescriptions</var> or <var>itemTypes</var> is
   * null, or any element of <var>itemNames</var> or <var>itemDescriptions</var> is a null or empty
   * string, or any element of <var>itemTypes</var> is null, or <var>itemNames</var> or
   * <var>itemDescriptions</var> or <var>itemTypes</var> are not of the same size. <br>&nbsp;
   * @throws OpenDataException If <var>itemNames</var> contains duplicate item names (case
   * sensitive, but leading and trailing whitespaces removed).
   */
  public CompositeType(String typeName,
      String description,
      String[] itemNames,
      String[] itemDescriptions,
      OpenType<?>[] itemTypes) throws OpenDataException {

    // Check and construct state defined by parent
    //
    super(CompositeData.class.getName(), typeName, description, false);

    // Check the 3 arrays are not null or empty (ie length==0) and that there is no null element or empty string in them
    //
    checkForNullElement(itemNames, "itemNames");
    checkForNullElement(itemDescriptions, "itemDescriptions");
    checkForNullElement(itemTypes, "itemTypes");
    checkForEmptyString(itemNames, "itemNames");
    checkForEmptyString(itemDescriptions, "itemDescriptions");

    // Check the sizes of the 3 arrays are the same
    //
    if ((itemNames.length != itemDescriptions.length) || (itemNames.length != itemTypes.length)) {
      throw new IllegalArgumentException(
          "Array arguments itemNames[], itemDescriptions[] and itemTypes[] " +
              "should be of same length (got " + itemNames.length + ", " +
              itemDescriptions.length + " and " + itemTypes.length + ").");
    }

    // Initialize internal "names to descriptions" and "names to types" sorted maps,
    // and, by doing so, check there are no duplicate item names
    //
    nameToDescription = new TreeMap<String, String>();
    nameToType = new TreeMap<String, OpenType<?>>();
    String key;
    for (int i = 0; i < itemNames.length; i++) {
      key = itemNames[i].trim();
      if (nameToDescription.containsKey(key)) {
        throw new OpenDataException("Argument's element itemNames[" + i + "]=\"" + itemNames[i] +
            "\" duplicates a previous item names.");
      }
      nameToDescription.put(key, itemDescriptions[i].trim());
      nameToType.put(key, itemTypes[i]);
    }
  }

  private static void checkForNullElement(Object[] arg, String argName) {
    if ((arg == null) || (arg.length == 0)) {
      throw new IllegalArgumentException("Argument " + argName + "[] cannot be null or empty.");
    }
    for (int i = 0; i < arg.length; i++) {
      if (arg[i] == null) {
        throw new IllegalArgumentException(
            "Argument's element " + argName + "[" + i + "] cannot be null.");
      }
    }
  }

  private static void checkForEmptyString(String[] arg, String argName) {
    for (int i = 0; i < arg.length; i++) {
      if (arg[i].trim().equals("")) {
        throw new IllegalArgumentException(
            "Argument's element " + argName + "[" + i + "] cannot be an empty string.");
      }
    }
  }

    /* *** Composite type specific information methods *** */

  /**
   * Returns <code>true</code> if this <code>CompositeType</code> instance defines an item
   * whose name is <var>itemName</var>.
   *
   * @param itemName the name of the item.
   * @return true if an item of this name is present.
   */
  public boolean containsKey(String itemName) {

    if (itemName == null) {
      return false;
    }
    return nameToDescription.containsKey(itemName);
  }

  /**
   * Returns the description of the item whose name is <var>itemName</var>,
   * or <code>null</code> if this <code>CompositeType</code> instance does not define any item
   * whose name is <var>itemName</var>.
   *
   * @param itemName the name of the item.
   * @return the description.
   */
  public String getDescription(String itemName) {

    if (itemName == null) {
      return null;
    }
    return nameToDescription.get(itemName);
  }

  /**
   * Returns the <i>open type</i> of the item whose name is <var>itemName</var>,
   * or <code>null</code> if this <code>CompositeType</code> instance does not define any item
   * whose name is <var>itemName</var>.
   *
   * @param itemName the name of the time.
   * @return the type.
   */
  public OpenType<?> getType(String itemName) {

    if (itemName == null) {
      return null;
    }
    return (OpenType<?>) nameToType.get(itemName);
  }

  /**
   * Returns an unmodifiable Set view of all the item names defined by this
   * <code>CompositeType</code> instance. The set's iterator will return the item names in ascending
   * order.
   *
   * @return a {@link Set} of {@link String}.
   */
  public Set<String> keySet() {

    // Initializes myNamesSet on first call
    if (myNamesSet == null) {
      myNamesSet = Collections.unmodifiableSet(nameToDescription.keySet());
    }

    return myNamesSet; // always return the same value
  }


  /**
   * Tests whether <var>obj</var> is a value which could be
   * described by this <code>CompositeType</code> instance.
   *
   * <p>If <var>obj</var> is null or is not an instance of
   * <code>javax.management.openmbean.CompositeData</code>,
   * <code>isValue</code> returns <code>false</code>.</p>
   *
   * <p>If <var>obj</var> is an instance of
   * <code>javax.management.openmbean.CompositeData</code>, then let
   * {@code ct} be its {@code CompositeType} as returned by {@link
   * CompositeData#getCompositeType()}.  The result is true if
   * {@code this} is <em>assignable from</em> {@code ct}.  This
   * means that:</p>
   *
   * <ul>
   * <li>{@link #getTypeName() this.getTypeName()} equals
   * {@code ct.getTypeName()}, and
   * <li>there are no item names present in {@code this} that are
   * not also present in {@code ct}, and
   * <li>for every item in {@code this}, its type is assignable from
   * the type of the corresponding item in {@code ct}.
   * </ul>
   *
   * <p>A {@code TabularType} is assignable from another {@code
   * TabularType} if they have the same {@linkplain
   * TabularType#getTypeName() typeName} and {@linkplain
   * TabularType#getIndexNames() index name list}, and the
   * {@linkplain TabularType#getRowType() row type} of the first is
   * assignable from the row type of the second.
   *
   * <p>An {@code ArrayType} is assignable from another {@code
   * ArrayType} if they have the same {@linkplain
   * ArrayType#getDimension() dimension}; and both are {@linkplain
   * ArrayType#isPrimitiveArray() primitive arrays} or neither is;
   * and the {@linkplain ArrayType#getElementOpenType() element
   * type} of the first is assignable from the element type of the
   * second.
   *
   * <p>In every other case, an {@code OpenType} is assignable from
   * another {@code OpenType} only if they are equal.</p>
   *
   * <p>These rules mean that extra items can be added to a {@code
   * CompositeData} without making it invalid for a {@code CompositeType}
   * that does not have those items.</p>
   *
   * @param obj the value whose open type is to be tested for compatibility with this
   * <code>CompositeType</code> instance.
   * @return <code>true</code> if <var>obj</var> is a value for this composite type,
   * <code>false</code> otherwise.
   */
  public boolean isValue(Object obj) {

    // if obj is null or not CompositeData, return false
    //
    if (!(obj instanceof CompositeData)) {
      return false;
    }

    // if obj is not a CompositeData, return false
    //
    CompositeData value = (CompositeData) obj;

    // test value's CompositeType is assignable to this CompositeType instance
    //
    CompositeType valueType = value.getCompositeType();
    return this.isAssignableFrom(valueType);
  }

  /**
   * Tests whether values of the given type can be assigned to this
   * open type.  The result is true if the given type is also a
   * CompositeType with the same name ({@link #getTypeName()}), and
   * every item in this type is also present in the given type with
   * the same name and assignable type.  There can be additional
   * items in the given type, which are ignored.
   *
   * @param ot the type to be tested.
   * @return true if {@code ot} is assignable to this open type.
   */
  @Override
  boolean isAssignableFrom(OpenType<?> ot) {
    if (!(ot instanceof CompositeType)) {
      return false;
    }
    CompositeType ct = (CompositeType) ot;
    if (!ct.getTypeName().equals(getTypeName())) {
      return false;
    }
    for (String key : keySet()) {
      OpenType<?> otItemType = ct.getType(key);
      OpenType<?> thisItemType = getType(key);
      if (otItemType == null ||
          !thisItemType.isAssignableFrom(otItemType)) {
        return false;
      }
    }
    return true;
  }


    /* *** Methods overriden from class Object *** */

  /**
   * Compares the specified <code>obj</code> parameter with this <code>CompositeType</code> instance
   * for equality. <p> Two <code>CompositeType</code> instances are equal if and only if all of the
   * following statements are true: <ul> <li>their type names are equal</li> <li>their items' names
   * and types are equal</li> </ul> <br>&nbsp;
   *
   * @param obj the object to be compared for equality with this <code>CompositeType</code>
   * instance; if <var>obj</var> is <code>null</code>, <code>equals</code> returns
   * <code>false</code>.
   * @return <code>true</code> if the specified object is equal to this <code>CompositeType</code>
   * instance.
   */
  public boolean equals(Object obj) {

    // if obj is null, return false
    //
    if (obj == null) {
      return false;
    }

    // if obj is not a CompositeType, return false
    //
    CompositeType other;
    try {
      other = (CompositeType) obj;
    } catch (ClassCastException e) {
      return false;
    }

    // Now, really test for equality between this CompositeType instance and the other
    //

    // their names should be equal
    if (!this.getTypeName().equals(other.getTypeName())) {
      return false;
    }

    // their items names and types should be equal
    if (!this.nameToType.equals(other.nameToType)) {
      return false;
    }

    // All tests for equality were successfull
    //
    return true;
  }

  /**
   * Returns the hash code value for this <code>CompositeType</code> instance. <p> The hash code of
   * a <code>CompositeType</code> instance is the sum of the hash codes of all elements of
   * information used in <code>equals</code> comparisons (ie: name, items names, items types). This
   * ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode()
   * </code> for any two <code>CompositeType</code> instances <code>t1</code> and <code>t2</code>,
   * as required by the general contract of the method {@link Object#hashCode() Object.hashCode()}.
   * <p> As <code>CompositeType</code> instances are immutable, the hash code for this instance is
   * calculated once, on the first call to <code>hashCode</code>, and then the same value is
   * returned for subsequent calls.
   *
   * @return the hash code value for this <code>CompositeType</code> instance
   */
  public int hashCode() {

    // Calculate the hash code value if it has not yet been done (ie 1st call to hashCode())
    //
    if (myHashCode == null) {
      int value = 0;
      value += this.getTypeName().hashCode();
      for (String key : nameToDescription.keySet()) {
        value += key.hashCode();
        value += this.nameToType.get(key).hashCode();
      }
      myHashCode = Integer.valueOf(value);
    }

    // return always the same hash code for this instance (immutable)
    //
    return myHashCode.intValue();
  }

  /**
   * Returns a string representation of this <code>CompositeType</code> instance. <p> The string
   * representation consists of the name of this class (ie <code>javax.management.openmbean.CompositeType</code>),
   * the type name for this instance, and the list of the items names and types string
   * representation of this instance. <p> As <code>CompositeType</code> instances are immutable, the
   * string representation for this instance is calculated once, on the first call to
   * <code>toString</code>, and then the same value is returned for subsequent calls.
   *
   * @return a string representation of this <code>CompositeType</code> instance
   */
  public String toString() {

    // Calculate the string representation if it has not yet been done (ie 1st call to toString())
    //
    if (myToString == null) {
      final StringBuilder result = new StringBuilder();
      result.append(this.getClass().getName());
      result.append("(name=");
      result.append(getTypeName());
      result.append(",items=(");
      int i = 0;
      Iterator<String> k = nameToType.keySet().iterator();
      String key;
      while (k.hasNext()) {
        key = k.next();
        if (i > 0) {
          result.append(",");
        }
        result.append("(itemName=");
        result.append(key);
        result.append(",itemType=");
        result.append(nameToType.get(key).toString() + ")");
        i++;
      }
      result.append("))");
      myToString = result.toString();
    }

    // return always the same string representation for this instance (immutable)
    //
    return myToString;
  }

}
